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Commit | Line | Data |
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53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
e83bebef | 2 | |
4f5dd394 | 3 | #include <sys/mount.h> |
07630cea | 4 | #include <linux/magic.h> |
e83bebef | 5 | |
b5efdb8a | 6 | #include "alloc-util.h" |
4f5dd394 | 7 | #include "escape.h" |
0996ef00 | 8 | #include "fd-util.h" |
ca78ad1d | 9 | #include "format-util.h" |
f4f15635 | 10 | #include "fs-util.h" |
e83bebef | 11 | #include "label.h" |
4f5dd394 | 12 | #include "mkdir.h" |
4349cd7c | 13 | #include "mount-util.h" |
049af8ad | 14 | #include "mountpoint-util.h" |
6bedfcbb LP |
15 | #include "nspawn-mount.h" |
16 | #include "parse-util.h" | |
4f5dd394 LP |
17 | #include "path-util.h" |
18 | #include "rm-rf.h" | |
e83bebef | 19 | #include "set.h" |
760877e9 | 20 | #include "sort-util.h" |
8fcde012 | 21 | #include "stat-util.h" |
07630cea | 22 | #include "string-util.h" |
4f5dd394 | 23 | #include "strv.h" |
e4de7287 | 24 | #include "tmpfile-util.h" |
ee104e11 | 25 | #include "user-util.h" |
e83bebef | 26 | |
88614c8a | 27 | CustomMount* custom_mount_add(CustomMount **l, size_t *n, CustomMountType t) { |
e83bebef LP |
28 | CustomMount *c, *ret; |
29 | ||
30 | assert(l); | |
31 | assert(n); | |
32 | assert(t >= 0); | |
33 | assert(t < _CUSTOM_MOUNT_TYPE_MAX); | |
34 | ||
aa484f35 | 35 | c = reallocarray(*l, *n + 1, sizeof(CustomMount)); |
e83bebef LP |
36 | if (!c) |
37 | return NULL; | |
38 | ||
39 | *l = c; | |
40 | ret = *l + *n; | |
41 | (*n)++; | |
42 | ||
43 | *ret = (CustomMount) { .type = t }; | |
44 | ||
45 | return ret; | |
46 | } | |
47 | ||
88614c8a LP |
48 | void custom_mount_free_all(CustomMount *l, size_t n) { |
49 | size_t i; | |
e83bebef LP |
50 | |
51 | for (i = 0; i < n; i++) { | |
52 | CustomMount *m = l + i; | |
53 | ||
54 | free(m->source); | |
55 | free(m->destination); | |
56 | free(m->options); | |
57 | ||
58 | if (m->work_dir) { | |
59 | (void) rm_rf(m->work_dir, REMOVE_ROOT|REMOVE_PHYSICAL); | |
60 | free(m->work_dir); | |
61 | } | |
62 | ||
c7a4890c LP |
63 | if (m->rm_rf_tmpdir) { |
64 | (void) rm_rf(m->rm_rf_tmpdir, REMOVE_ROOT|REMOVE_PHYSICAL); | |
65 | free(m->rm_rf_tmpdir); | |
66 | } | |
67 | ||
e83bebef | 68 | strv_free(m->lower); |
de40a303 | 69 | free(m->type_argument); |
e83bebef LP |
70 | } |
71 | ||
72 | free(l); | |
73 | } | |
74 | ||
93bab288 | 75 | static int custom_mount_compare(const CustomMount *a, const CustomMount *b) { |
e83bebef LP |
76 | int r; |
77 | ||
93bab288 | 78 | r = path_compare(a->destination, b->destination); |
e83bebef LP |
79 | if (r != 0) |
80 | return r; | |
81 | ||
93bab288 | 82 | return CMP(a->type, b->type); |
e83bebef LP |
83 | } |
84 | ||
86c0dd4a LP |
85 | static bool source_path_is_valid(const char *p) { |
86 | assert(p); | |
87 | ||
88 | if (*p == '+') | |
89 | p++; | |
90 | ||
91 | return path_is_absolute(p); | |
92 | } | |
93 | ||
94 | static char *resolve_source_path(const char *dest, const char *source) { | |
95 | ||
96 | if (!source) | |
97 | return NULL; | |
98 | ||
99 | if (source[0] == '+') | |
c6134d3e | 100 | return path_join(dest, source + 1); |
86c0dd4a LP |
101 | |
102 | return strdup(source); | |
103 | } | |
104 | ||
d0556c55 LP |
105 | static int allocate_temporary_source(CustomMount *m) { |
106 | assert(m); | |
107 | assert(!m->source); | |
108 | assert(!m->rm_rf_tmpdir); | |
109 | ||
110 | m->rm_rf_tmpdir = strdup("/var/tmp/nspawn-temp-XXXXXX"); | |
111 | if (!m->rm_rf_tmpdir) | |
112 | return log_oom(); | |
113 | ||
114 | if (!mkdtemp(m->rm_rf_tmpdir)) { | |
115 | m->rm_rf_tmpdir = mfree(m->rm_rf_tmpdir); | |
116 | return log_error_errno(errno, "Failed to acquire temporary directory: %m"); | |
117 | } | |
118 | ||
119 | m->source = path_join(m->rm_rf_tmpdir, "src"); | |
120 | if (!m->source) | |
121 | return log_oom(); | |
122 | ||
123 | if (mkdir(m->source, 0755) < 0) | |
124 | return log_error_errno(errno, "Failed to create %s: %m", m->source); | |
125 | ||
126 | return 0; | |
127 | } | |
128 | ||
88614c8a LP |
129 | int custom_mount_prepare_all(const char *dest, CustomMount *l, size_t n) { |
130 | size_t i; | |
86c0dd4a LP |
131 | int r; |
132 | ||
133 | /* Prepare all custom mounts. This will make source we know all temporary directories. This is called in the | |
134 | * parent process, so that we know the temporary directories to remove on exit before we fork off the | |
135 | * children. */ | |
136 | ||
137 | assert(l || n == 0); | |
138 | ||
139 | /* Order the custom mounts, and make sure we have a working directory */ | |
93bab288 | 140 | typesafe_qsort(l, n, custom_mount_compare); |
86c0dd4a LP |
141 | |
142 | for (i = 0; i < n; i++) { | |
143 | CustomMount *m = l + i; | |
144 | ||
de40a303 LP |
145 | /* /proc we mount in the inner child, i.e. when we acquired CLONE_NEWPID. All other mounts we mount |
146 | * already in the outer child, so that the mounts are already established before CLONE_NEWPID and in | |
147 | * particular CLONE_NEWUSER. This also means any custom mounts below /proc also need to be mounted in | |
148 | * the inner child, not the outer one. Determine this here. */ | |
149 | m->in_userns = path_startswith(m->destination, "/proc"); | |
86c0dd4a | 150 | |
de40a303 LP |
151 | if (m->type == CUSTOM_MOUNT_BIND) { |
152 | if (m->source) { | |
153 | char *s; | |
86c0dd4a | 154 | |
de40a303 LP |
155 | s = resolve_source_path(dest, m->source); |
156 | if (!s) | |
157 | return log_oom(); | |
c7a4890c | 158 | |
de40a303 LP |
159 | free_and_replace(m->source, s); |
160 | } else { | |
161 | /* No source specified? In that case, use a throw-away temporary directory in /var/tmp */ | |
c7a4890c | 162 | |
d0556c55 LP |
163 | r = allocate_temporary_source(m); |
164 | if (r < 0) | |
165 | return r; | |
de40a303 | 166 | } |
86c0dd4a LP |
167 | } |
168 | ||
169 | if (m->type == CUSTOM_MOUNT_OVERLAY) { | |
170 | char **j; | |
171 | ||
172 | STRV_FOREACH(j, m->lower) { | |
173 | char *s; | |
174 | ||
175 | s = resolve_source_path(dest, *j); | |
176 | if (!s) | |
177 | return log_oom(); | |
178 | ||
10af01a5 | 179 | free_and_replace(*j, s); |
86c0dd4a LP |
180 | } |
181 | ||
d0556c55 LP |
182 | if (m->source) { |
183 | char *s; | |
184 | ||
185 | s = resolve_source_path(dest, m->source); | |
186 | if (!s) | |
187 | return log_oom(); | |
188 | ||
189 | free_and_replace(m->source, s); | |
190 | } else { | |
191 | r = allocate_temporary_source(m); | |
192 | if (r < 0) | |
193 | return r; | |
194 | } | |
195 | ||
86c0dd4a LP |
196 | if (m->work_dir) { |
197 | char *s; | |
198 | ||
199 | s = resolve_source_path(dest, m->work_dir); | |
200 | if (!s) | |
201 | return log_oom(); | |
202 | ||
10af01a5 | 203 | free_and_replace(m->work_dir, s); |
86c0dd4a | 204 | } else { |
86c0dd4a LP |
205 | r = tempfn_random(m->source, NULL, &m->work_dir); |
206 | if (r < 0) | |
207 | return log_error_errno(r, "Failed to acquire working directory: %m"); | |
208 | } | |
209 | ||
210 | (void) mkdir_label(m->work_dir, 0700); | |
211 | } | |
212 | } | |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
88614c8a | 217 | int bind_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
e83bebef LP |
218 | _cleanup_free_ char *source = NULL, *destination = NULL, *opts = NULL; |
219 | const char *p = s; | |
220 | CustomMount *m; | |
221 | int r; | |
222 | ||
223 | assert(l); | |
224 | assert(n); | |
225 | ||
226 | r = extract_many_words(&p, ":", EXTRACT_DONT_COALESCE_SEPARATORS, &source, &destination, NULL); | |
227 | if (r < 0) | |
228 | return r; | |
229 | if (r == 0) | |
230 | return -EINVAL; | |
e83bebef | 231 | if (r == 1) { |
86c0dd4a | 232 | destination = strdup(source[0] == '+' ? source+1 : source); |
e83bebef LP |
233 | if (!destination) |
234 | return -ENOMEM; | |
235 | } | |
e83bebef LP |
236 | if (r == 2 && !isempty(p)) { |
237 | opts = strdup(p); | |
238 | if (!opts) | |
239 | return -ENOMEM; | |
240 | } | |
241 | ||
c7a4890c | 242 | if (isempty(source)) |
0e636bf5 | 243 | source = mfree(source); |
c7a4890c | 244 | else if (!source_path_is_valid(source)) |
e83bebef | 245 | return -EINVAL; |
c7a4890c | 246 | |
e83bebef LP |
247 | if (!path_is_absolute(destination)) |
248 | return -EINVAL; | |
249 | ||
250 | m = custom_mount_add(l, n, CUSTOM_MOUNT_BIND); | |
251 | if (!m) | |
48cbe5f8 | 252 | return -ENOMEM; |
e83bebef | 253 | |
0e636bf5 ZJS |
254 | m->source = TAKE_PTR(source); |
255 | m->destination = TAKE_PTR(destination); | |
e83bebef | 256 | m->read_only = read_only; |
0e636bf5 | 257 | m->options = TAKE_PTR(opts); |
de40a303 | 258 | |
e83bebef LP |
259 | return 0; |
260 | } | |
261 | ||
88614c8a | 262 | int tmpfs_mount_parse(CustomMount **l, size_t *n, const char *s) { |
e83bebef LP |
263 | _cleanup_free_ char *path = NULL, *opts = NULL; |
264 | const char *p = s; | |
265 | CustomMount *m; | |
266 | int r; | |
267 | ||
268 | assert(l); | |
269 | assert(n); | |
270 | assert(s); | |
271 | ||
272 | r = extract_first_word(&p, &path, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
273 | if (r < 0) | |
274 | return r; | |
275 | if (r == 0) | |
276 | return -EINVAL; | |
277 | ||
278 | if (isempty(p)) | |
279 | opts = strdup("mode=0755"); | |
280 | else | |
281 | opts = strdup(p); | |
282 | if (!opts) | |
283 | return -ENOMEM; | |
284 | ||
285 | if (!path_is_absolute(path)) | |
286 | return -EINVAL; | |
287 | ||
288 | m = custom_mount_add(l, n, CUSTOM_MOUNT_TMPFS); | |
289 | if (!m) | |
290 | return -ENOMEM; | |
291 | ||
1cc6c93a YW |
292 | m->destination = TAKE_PTR(path); |
293 | m->options = TAKE_PTR(opts); | |
e83bebef | 294 | |
e83bebef LP |
295 | return 0; |
296 | } | |
297 | ||
88614c8a | 298 | int overlay_mount_parse(CustomMount **l, size_t *n, const char *s, bool read_only) { |
ad85779a LP |
299 | _cleanup_free_ char *upper = NULL, *destination = NULL; |
300 | _cleanup_strv_free_ char **lower = NULL; | |
301 | CustomMount *m; | |
86c0dd4a | 302 | int k; |
ad85779a | 303 | |
86c0dd4a LP |
304 | k = strv_split_extract(&lower, s, ":", EXTRACT_DONT_COALESCE_SEPARATORS); |
305 | if (k < 0) | |
306 | return k; | |
ad85779a LP |
307 | if (k < 2) |
308 | return -EADDRNOTAVAIL; | |
309 | if (k == 2) { | |
86c0dd4a LP |
310 | /* If two parameters are specified, the first one is the lower, the second one the upper directory. And |
311 | * we'll also define the destination mount point the same as the upper. */ | |
312 | ||
313 | if (!source_path_is_valid(lower[0]) || | |
314 | !source_path_is_valid(lower[1])) | |
315 | return -EINVAL; | |
316 | ||
ae2a15bc | 317 | upper = TAKE_PTR(lower[1]); |
ad85779a | 318 | |
86c0dd4a | 319 | destination = strdup(upper[0] == '+' ? upper+1 : upper); /* take the destination without "+" prefix */ |
ad85779a LP |
320 | if (!destination) |
321 | return -ENOMEM; | |
ad85779a | 322 | } else { |
c7a4890c | 323 | char **i; |
86c0dd4a LP |
324 | |
325 | /* If more than two parameters are specified, the last one is the destination, the second to last one | |
326 | * the "upper", and all before that the "lower" directories. */ | |
327 | ||
ad85779a | 328 | destination = lower[k - 1]; |
ae2a15bc | 329 | upper = TAKE_PTR(lower[k - 2]); |
86c0dd4a | 330 | |
c7a4890c LP |
331 | STRV_FOREACH(i, lower) |
332 | if (!source_path_is_valid(*i)) | |
333 | return -EINVAL; | |
334 | ||
335 | /* If the upper directory is unspecified, then let's create it automatically as a throw-away directory | |
336 | * in /var/tmp */ | |
337 | if (isempty(upper)) | |
1d0c1146 | 338 | upper = mfree(upper); |
c7a4890c LP |
339 | else if (!source_path_is_valid(upper)) |
340 | return -EINVAL; | |
341 | ||
86c0dd4a LP |
342 | if (!path_is_absolute(destination)) |
343 | return -EINVAL; | |
ad85779a LP |
344 | } |
345 | ||
346 | m = custom_mount_add(l, n, CUSTOM_MOUNT_OVERLAY); | |
347 | if (!m) | |
348 | return -ENOMEM; | |
349 | ||
1cc6c93a YW |
350 | m->destination = TAKE_PTR(destination); |
351 | m->source = TAKE_PTR(upper); | |
352 | m->lower = TAKE_PTR(lower); | |
ad85779a LP |
353 | m->read_only = read_only; |
354 | ||
ad85779a LP |
355 | return 0; |
356 | } | |
357 | ||
de40a303 LP |
358 | int inaccessible_mount_parse(CustomMount **l, size_t *n, const char *s) { |
359 | _cleanup_free_ char *path = NULL; | |
360 | CustomMount *m; | |
361 | ||
362 | assert(l); | |
363 | assert(n); | |
364 | assert(s); | |
365 | ||
366 | if (!path_is_absolute(s)) | |
367 | return -EINVAL; | |
368 | ||
369 | path = strdup(s); | |
370 | if (!path) | |
371 | return -ENOMEM; | |
372 | ||
373 | m = custom_mount_add(l, n, CUSTOM_MOUNT_INACCESSIBLE); | |
374 | if (!m) | |
375 | return -ENOMEM; | |
376 | ||
377 | m->destination = TAKE_PTR(path); | |
378 | return 0; | |
379 | } | |
380 | ||
04029482 | 381 | int tmpfs_patch_options( |
e83bebef | 382 | const char *options, |
2fa017f1 | 383 | uid_t uid_shift, |
e83bebef LP |
384 | const char *selinux_apifs_context, |
385 | char **ret) { | |
386 | ||
387 | char *buf = NULL; | |
388 | ||
2fa017f1 | 389 | if (uid_shift != UID_INVALID) { |
9aa2169e | 390 | if (asprintf(&buf, "%s%suid=" UID_FMT ",gid=" UID_FMT, |
87e4e28d | 391 | strempty(options), options ? "," : "", |
9aa2169e | 392 | uid_shift, uid_shift) < 0) |
e83bebef LP |
393 | return -ENOMEM; |
394 | ||
395 | options = buf; | |
396 | } | |
397 | ||
349cc4a5 | 398 | #if HAVE_SELINUX |
e83bebef LP |
399 | if (selinux_apifs_context) { |
400 | char *t; | |
401 | ||
87e4e28d | 402 | t = strjoin(strempty(options), options ? "," : "", |
9aa2169e ZJS |
403 | "context=\"", selinux_apifs_context, "\""); |
404 | free(buf); | |
405 | if (!t) | |
e83bebef | 406 | return -ENOMEM; |
e83bebef | 407 | |
e83bebef LP |
408 | buf = t; |
409 | } | |
410 | #endif | |
411 | ||
0996ef00 CB |
412 | if (!buf && options) { |
413 | buf = strdup(options); | |
414 | if (!buf) | |
415 | return -ENOMEM; | |
416 | } | |
e83bebef | 417 | *ret = buf; |
0996ef00 | 418 | |
e83bebef LP |
419 | return !!buf; |
420 | } | |
421 | ||
4f086aab | 422 | int mount_sysfs(const char *dest, MountSettingsMask mount_settings) { |
d8fc6a00 | 423 | const char *full, *top, *x; |
d1678248 | 424 | int r; |
4f086aab | 425 | unsigned long extra_flags = 0; |
d8fc6a00 LP |
426 | |
427 | top = prefix_roota(dest, "/sys"); | |
40fd52f2 | 428 | r = path_is_fs_type(top, SYSFS_MAGIC); |
d1678248 ILG |
429 | if (r < 0) |
430 | return log_error_errno(r, "Failed to determine filesystem type of %s: %m", top); | |
431 | /* /sys might already be mounted as sysfs by the outer child in the | |
432 | * !netns case. In this case, it's all good. Don't touch it because we | |
433 | * don't have the right to do so, see https://github.com/systemd/systemd/issues/1555. | |
434 | */ | |
435 | if (r > 0) | |
436 | return 0; | |
437 | ||
d8fc6a00 LP |
438 | full = prefix_roota(top, "/full"); |
439 | ||
440 | (void) mkdir(full, 0755); | |
441 | ||
bd6609eb | 442 | if (FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO)) |
4f086aab SU |
443 | extra_flags |= MS_RDONLY; |
444 | ||
60e76d48 | 445 | r = mount_verbose(LOG_ERR, "sysfs", full, "sysfs", |
4f086aab | 446 | MS_NOSUID|MS_NOEXEC|MS_NODEV|extra_flags, NULL); |
60e76d48 ZJS |
447 | if (r < 0) |
448 | return r; | |
d8fc6a00 LP |
449 | |
450 | FOREACH_STRING(x, "block", "bus", "class", "dev", "devices", "kernel") { | |
451 | _cleanup_free_ char *from = NULL, *to = NULL; | |
452 | ||
c6134d3e | 453 | from = path_join(full, x); |
d8fc6a00 LP |
454 | if (!from) |
455 | return log_oom(); | |
456 | ||
c6134d3e | 457 | to = path_join(top, x); |
d8fc6a00 LP |
458 | if (!to) |
459 | return log_oom(); | |
460 | ||
461 | (void) mkdir(to, 0755); | |
462 | ||
60e76d48 ZJS |
463 | r = mount_verbose(LOG_ERR, from, to, NULL, MS_BIND, NULL); |
464 | if (r < 0) | |
465 | return r; | |
d8fc6a00 | 466 | |
60e76d48 | 467 | r = mount_verbose(LOG_ERR, NULL, to, NULL, |
4f086aab | 468 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); |
60e76d48 ZJS |
469 | if (r < 0) |
470 | return r; | |
d8fc6a00 LP |
471 | } |
472 | ||
60e76d48 ZJS |
473 | r = umount_verbose(full); |
474 | if (r < 0) | |
475 | return r; | |
d8fc6a00 LP |
476 | |
477 | if (rmdir(full) < 0) | |
478 | return log_error_errno(errno, "Failed to remove %s: %m", full); | |
479 | ||
0996ef00 CB |
480 | /* Create mountpoint for cgroups. Otherwise we are not allowed since we |
481 | * remount /sys read-only. | |
482 | */ | |
677a72cd LS |
483 | x = prefix_roota(top, "/fs/cgroup"); |
484 | (void) mkdir_p(x, 0755); | |
d8fc6a00 | 485 | |
60e76d48 | 486 | return mount_verbose(LOG_ERR, NULL, top, NULL, |
4f086aab | 487 | MS_BIND|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT|extra_flags, NULL); |
d8fc6a00 LP |
488 | } |
489 | ||
9c0fad5f | 490 | static int mkdir_userns(const char *path, mode_t mode, uid_t uid_shift) { |
63eae723 EV |
491 | int r; |
492 | ||
493 | assert(path); | |
494 | ||
dae8b82e ZJS |
495 | r = mkdir_errno_wrapper(path, mode); |
496 | if (r < 0 && r != -EEXIST) | |
497 | return r; | |
63eae723 | 498 | |
9c0fad5f | 499 | if (uid_shift == UID_INVALID) |
acbbf69b LP |
500 | return 0; |
501 | ||
dae8b82e | 502 | if (lchown(path, uid_shift, uid_shift) < 0) |
acbbf69b | 503 | return -errno; |
63eae723 EV |
504 | |
505 | return 0; | |
506 | } | |
507 | ||
9c0fad5f | 508 | static int mkdir_userns_p(const char *prefix, const char *path, mode_t mode, uid_t uid_shift) { |
63eae723 EV |
509 | const char *p, *e; |
510 | int r; | |
511 | ||
512 | assert(path); | |
513 | ||
514 | if (prefix && !path_startswith(path, prefix)) | |
515 | return -ENOTDIR; | |
516 | ||
517 | /* create every parent directory in the path, except the last component */ | |
518 | p = path + strspn(path, "/"); | |
519 | for (;;) { | |
520 | char t[strlen(path) + 1]; | |
521 | ||
522 | e = p + strcspn(p, "/"); | |
523 | p = e + strspn(e, "/"); | |
524 | ||
525 | /* Is this the last component? If so, then we're done */ | |
526 | if (*p == 0) | |
527 | break; | |
528 | ||
529 | memcpy(t, path, e - path); | |
530 | t[e-path] = 0; | |
531 | ||
532 | if (prefix && path_startswith(prefix, t)) | |
533 | continue; | |
534 | ||
9c0fad5f | 535 | r = mkdir_userns(t, mode, uid_shift); |
63eae723 EV |
536 | if (r < 0) |
537 | return r; | |
538 | } | |
539 | ||
9c0fad5f | 540 | return mkdir_userns(path, mode, uid_shift); |
63eae723 EV |
541 | } |
542 | ||
e83bebef | 543 | int mount_all(const char *dest, |
4f086aab | 544 | MountSettingsMask mount_settings, |
2fa017f1 | 545 | uid_t uid_shift, |
e83bebef LP |
546 | const char *selinux_apifs_context) { |
547 | ||
de40a303 LP |
548 | #define PROC_INACCESSIBLE_REG(path) \ |
549 | { "/run/systemd/inaccessible/reg", (path), NULL, NULL, MS_BIND, \ | |
550 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
d4b653c5 LP |
551 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ |
552 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
553 | ||
554 | #define PROC_READ_ONLY(path) \ | |
555 | { (path), (path), NULL, NULL, MS_BIND, \ | |
556 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ \ | |
557 | { NULL, (path), NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, \ | |
558 | MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO } /* Then, make it r/o */ | |
559 | ||
e83bebef LP |
560 | typedef struct MountPoint { |
561 | const char *what; | |
562 | const char *where; | |
563 | const char *type; | |
564 | const char *options; | |
565 | unsigned long flags; | |
4f086aab | 566 | MountSettingsMask mount_settings; |
e83bebef LP |
567 | } MountPoint; |
568 | ||
569 | static const MountPoint mount_table[] = { | |
d4b653c5 LP |
570 | /* First we list inner child mounts (i.e. mounts applied *after* entering user namespacing) */ |
571 | { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
572 | MOUNT_FATAL|MOUNT_IN_USERNS }, | |
573 | ||
574 | { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND, | |
575 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* Bind mount first ... */ | |
576 | ||
577 | { "/proc/sys/net", "/proc/sys/net", NULL, NULL, MS_BIND, | |
578 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO|MOUNT_APPLY_APIVFS_NETNS }, /* (except for this) */ | |
579 | ||
580 | { NULL, "/proc/sys", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
581 | MOUNT_FATAL|MOUNT_IN_USERNS|MOUNT_APPLY_APIVFS_RO }, /* ... then, make it r/o */ | |
582 | ||
583 | /* Make these files inaccessible to container payloads: they potentially leak information about kernel | |
584 | * internals or the host's execution environment to the container */ | |
de40a303 LP |
585 | PROC_INACCESSIBLE_REG("/proc/kallsyms"), |
586 | PROC_INACCESSIBLE_REG("/proc/kcore"), | |
587 | PROC_INACCESSIBLE_REG("/proc/keys"), | |
588 | PROC_INACCESSIBLE_REG("/proc/sysrq-trigger"), | |
589 | PROC_INACCESSIBLE_REG("/proc/timer_list"), | |
d4b653c5 LP |
590 | |
591 | /* Make these directories read-only to container payloads: they show hardware information, and in some | |
592 | * cases contain tunables the container really shouldn't have access to. */ | |
593 | PROC_READ_ONLY("/proc/acpi"), | |
594 | PROC_READ_ONLY("/proc/apm"), | |
595 | PROC_READ_ONLY("/proc/asound"), | |
596 | PROC_READ_ONLY("/proc/bus"), | |
597 | PROC_READ_ONLY("/proc/fs"), | |
598 | PROC_READ_ONLY("/proc/irq"), | |
599 | PROC_READ_ONLY("/proc/scsi"), | |
600 | ||
849b9b85 LP |
601 | { "mqueue", "/dev/mqueue", "mqueue", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, |
602 | MOUNT_IN_USERNS }, | |
603 | ||
d4b653c5 LP |
604 | /* Then we list outer child mounts (i.e. mounts applied *before* entering user namespacing) */ |
605 | { "tmpfs", "/tmp", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
1099ceeb | 606 | MOUNT_FATAL|MOUNT_APPLY_TMPFS_TMP }, |
03d0f4b5 | 607 | { "tmpfs", "/sys", "tmpfs", "mode=555", MS_NOSUID|MS_NOEXEC|MS_NODEV, |
d4b653c5 LP |
608 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_NETNS }, |
609 | { "sysfs", "/sys", "sysfs", NULL, MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
610 | MOUNT_FATAL|MOUNT_APPLY_APIVFS_RO }, /* skipped if above was mounted */ | |
611 | { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV, | |
612 | MOUNT_FATAL }, /* skipped if above was mounted */ | |
613 | { "tmpfs", "/dev", "tmpfs", "mode=755", MS_NOSUID|MS_STRICTATIME, | |
614 | MOUNT_FATAL }, | |
615 | { "tmpfs", "/dev/shm", "tmpfs", "mode=1777", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
616 | MOUNT_FATAL }, | |
617 | { "tmpfs", "/run", "tmpfs", "mode=755", MS_NOSUID|MS_NODEV|MS_STRICTATIME, | |
618 | MOUNT_FATAL }, | |
619 | ||
349cc4a5 | 620 | #if HAVE_SELINUX |
d4b653c5 LP |
621 | { "/sys/fs/selinux", "/sys/fs/selinux", NULL, NULL, MS_BIND, |
622 | 0 }, /* Bind mount first */ | |
623 | { NULL, "/sys/fs/selinux", NULL, NULL, MS_BIND|MS_RDONLY|MS_NOSUID|MS_NOEXEC|MS_NODEV|MS_REMOUNT, | |
624 | 0 }, /* Then, make it r/o */ | |
e83bebef LP |
625 | #endif |
626 | }; | |
627 | ||
bd6609eb DDM |
628 | bool use_userns = FLAGS_SET(mount_settings, MOUNT_USE_USERNS); |
629 | bool netns = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_NETNS); | |
630 | bool ro = FLAGS_SET(mount_settings, MOUNT_APPLY_APIVFS_RO); | |
631 | bool in_userns = FLAGS_SET(mount_settings, MOUNT_IN_USERNS); | |
632 | bool tmpfs_tmp = FLAGS_SET(mount_settings, MOUNT_APPLY_TMPFS_TMP); | |
d4b653c5 | 633 | size_t k; |
88614c8a | 634 | int r; |
e83bebef LP |
635 | |
636 | for (k = 0; k < ELEMENTSOF(mount_table); k++) { | |
637 | _cleanup_free_ char *where = NULL, *options = NULL; | |
de40a303 | 638 | const char *o; |
bd6609eb | 639 | bool fatal = FLAGS_SET(mount_table[k].mount_settings, MOUNT_FATAL); |
4f086aab | 640 | |
bd6609eb | 641 | if (in_userns != FLAGS_SET(mount_table[k].mount_settings, MOUNT_IN_USERNS)) |
4f086aab | 642 | continue; |
e83bebef | 643 | |
bd6609eb | 644 | if (!netns && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_NETNS)) |
d1678248 ILG |
645 | continue; |
646 | ||
bd6609eb | 647 | if (!ro && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_APIVFS_RO)) |
e83bebef LP |
648 | continue; |
649 | ||
bd6609eb | 650 | if (!tmpfs_tmp && FLAGS_SET(mount_table[k].mount_settings, MOUNT_APPLY_TMPFS_TMP)) |
1099ceeb LP |
651 | continue; |
652 | ||
a5648b80 | 653 | r = chase_symlinks(mount_table[k].where, dest, CHASE_NONEXISTENT|CHASE_PREFIX_ROOT, &where, NULL); |
8ce48cf0 | 654 | if (r < 0) |
ec57bd42 | 655 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, mount_table[k].where); |
e83bebef | 656 | |
e83bebef | 657 | /* Skip this entry if it is not a remount. */ |
de40a303 LP |
658 | if (mount_table[k].what) { |
659 | r = path_is_mount_point(where, NULL, 0); | |
660 | if (r < 0 && r != -ENOENT) | |
661 | return log_error_errno(r, "Failed to detect whether %s is a mount point: %m", where); | |
662 | if (r > 0) | |
663 | continue; | |
664 | } | |
e83bebef | 665 | |
9c0fad5f | 666 | r = mkdir_userns_p(dest, where, 0755, (use_userns && !in_userns) ? uid_shift : UID_INVALID); |
920a7899 | 667 | if (r < 0 && r != -EEXIST) { |
4f13e534 | 668 | if (fatal && r != -EROFS) |
e83bebef LP |
669 | return log_error_errno(r, "Failed to create directory %s: %m", where); |
670 | ||
201b13c8 | 671 | log_debug_errno(r, "Failed to create directory %s: %m", where); |
4f13e534 LT |
672 | /* If we failed mkdir() or chown() due to the root |
673 | * directory being read only, attempt to mount this fs | |
674 | * anyway and let mount_verbose log any errors */ | |
675 | if (r != -EROFS) | |
676 | continue; | |
e83bebef LP |
677 | } |
678 | ||
679 | o = mount_table[k].options; | |
680 | if (streq_ptr(mount_table[k].type, "tmpfs")) { | |
2fa017f1 | 681 | r = tmpfs_patch_options(o, in_userns ? 0 : uid_shift, selinux_apifs_context, &options); |
e83bebef LP |
682 | if (r < 0) |
683 | return log_oom(); | |
684 | if (r > 0) | |
685 | o = options; | |
686 | } | |
687 | ||
4f086aab | 688 | r = mount_verbose(fatal ? LOG_ERR : LOG_DEBUG, |
de40a303 | 689 | mount_table[k].what, |
60e76d48 ZJS |
690 | where, |
691 | mount_table[k].type, | |
692 | mount_table[k].flags, | |
693 | o); | |
4f086aab | 694 | if (r < 0 && fatal) |
60e76d48 | 695 | return r; |
e83bebef LP |
696 | } |
697 | ||
698 | return 0; | |
699 | } | |
700 | ||
a11fd406 ILG |
701 | static int parse_mount_bind_options(const char *options, unsigned long *mount_flags, char **mount_opts) { |
702 | const char *p = options; | |
703 | unsigned long flags = *mount_flags; | |
704 | char *opts = NULL; | |
705 | int r; | |
706 | ||
707 | assert(options); | |
708 | ||
709 | for (;;) { | |
710 | _cleanup_free_ char *word = NULL; | |
711 | ||
712 | r = extract_first_word(&p, &word, ",", 0); | |
713 | if (r < 0) | |
714 | return log_error_errno(r, "Failed to extract mount option: %m"); | |
715 | if (r == 0) | |
716 | break; | |
717 | ||
718 | if (streq(word, "rbind")) | |
719 | flags |= MS_REC; | |
720 | else if (streq(word, "norbind")) | |
721 | flags &= ~MS_REC; | |
722 | else { | |
38288f0b FS |
723 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), |
724 | "Invalid bind mount option: %s", | |
725 | word); | |
a11fd406 ILG |
726 | } |
727 | } | |
728 | ||
729 | *mount_flags = flags; | |
730 | /* in the future mount_opts will hold string options for mount(2) */ | |
731 | *mount_opts = opts; | |
732 | ||
733 | return 0; | |
734 | } | |
735 | ||
e83bebef | 736 | static int mount_bind(const char *dest, CustomMount *m) { |
a11fd406 ILG |
737 | _cleanup_free_ char *mount_opts = NULL, *where = NULL; |
738 | unsigned long mount_flags = MS_BIND | MS_REC; | |
68cf43c3 | 739 | struct stat source_st, dest_st; |
e83bebef LP |
740 | int r; |
741 | ||
86c0dd4a | 742 | assert(dest); |
e83bebef LP |
743 | assert(m); |
744 | ||
a11fd406 ILG |
745 | if (m->options) { |
746 | r = parse_mount_bind_options(m->options, &mount_flags, &mount_opts); | |
747 | if (r < 0) | |
748 | return r; | |
749 | } | |
750 | ||
e83bebef LP |
751 | if (stat(m->source, &source_st) < 0) |
752 | return log_error_errno(errno, "Failed to stat %s: %m", m->source); | |
753 | ||
a5648b80 | 754 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 755 | if (r < 0) |
ec57bd42 | 756 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
757 | if (r > 0) { /* Path exists already? */ |
758 | ||
759 | if (stat(where, &dest_st) < 0) | |
760 | return log_error_errno(errno, "Failed to stat %s: %m", where); | |
e83bebef | 761 | |
baaa35ad ZJS |
762 | if (S_ISDIR(source_st.st_mode) && !S_ISDIR(dest_st.st_mode)) |
763 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
764 | "Cannot bind mount directory %s on file %s.", | |
765 | m->source, where); | |
766 | ||
767 | if (!S_ISDIR(source_st.st_mode) && S_ISDIR(dest_st.st_mode)) | |
768 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
769 | "Cannot bind mount file %s on directory %s.", | |
770 | m->source, where); | |
e83bebef | 771 | |
8ce48cf0 | 772 | } else { /* Path doesn't exist yet? */ |
e83bebef LP |
773 | r = mkdir_parents_label(where, 0755); |
774 | if (r < 0) | |
775 | return log_error_errno(r, "Failed to make parents of %s: %m", where); | |
b97e83cb BN |
776 | |
777 | /* Create the mount point. Any non-directory file can be | |
778 | * mounted on any non-directory file (regular, fifo, socket, | |
779 | * char, block). | |
780 | */ | |
781 | if (S_ISDIR(source_st.st_mode)) | |
782 | r = mkdir_label(where, 0755); | |
783 | else | |
784 | r = touch(where); | |
785 | if (r < 0) | |
786 | return log_error_errno(r, "Failed to create mount point %s: %m", where); | |
8ce48cf0 | 787 | } |
e83bebef | 788 | |
a11fd406 | 789 | r = mount_verbose(LOG_ERR, m->source, where, NULL, mount_flags, mount_opts); |
60e76d48 ZJS |
790 | if (r < 0) |
791 | return r; | |
e83bebef LP |
792 | |
793 | if (m->read_only) { | |
64e82c19 | 794 | r = bind_remount_recursive(where, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
795 | if (r < 0) |
796 | return log_error_errno(r, "Read-only bind mount failed: %m"); | |
797 | } | |
798 | ||
799 | return 0; | |
800 | } | |
801 | ||
e091a5df | 802 | static int mount_tmpfs(const char *dest, CustomMount *m, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef | 803 | |
68cf43c3 LP |
804 | const char *options; |
805 | _cleanup_free_ char *buf = NULL, *where = NULL; | |
e83bebef LP |
806 | int r; |
807 | ||
808 | assert(dest); | |
809 | assert(m); | |
810 | ||
a5648b80 | 811 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 812 | if (r < 0) |
ec57bd42 | 813 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
814 | if (r == 0) { /* Doesn't exist yet? */ |
815 | r = mkdir_p_label(where, 0755); | |
816 | if (r < 0) | |
817 | return log_error_errno(r, "Creating mount point for tmpfs %s failed: %m", where); | |
818 | } | |
e83bebef | 819 | |
2fa017f1 | 820 | r = tmpfs_patch_options(m->options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
821 | if (r < 0) |
822 | return log_oom(); | |
823 | options = r > 0 ? buf : m->options; | |
824 | ||
60e76d48 | 825 | return mount_verbose(LOG_ERR, "tmpfs", where, "tmpfs", MS_NODEV|MS_STRICTATIME, options); |
e83bebef LP |
826 | } |
827 | ||
86c0dd4a | 828 | static char *joined_and_escaped_lower_dirs(char **lower) { |
e83bebef LP |
829 | _cleanup_strv_free_ char **sv = NULL; |
830 | ||
831 | sv = strv_copy(lower); | |
832 | if (!sv) | |
833 | return NULL; | |
834 | ||
835 | strv_reverse(sv); | |
836 | ||
837 | if (!strv_shell_escape(sv, ",:")) | |
838 | return NULL; | |
839 | ||
840 | return strv_join(sv, ":"); | |
841 | } | |
842 | ||
843 | static int mount_overlay(const char *dest, CustomMount *m) { | |
86c0dd4a | 844 | _cleanup_free_ char *lower = NULL, *where = NULL, *escaped_source = NULL; |
68cf43c3 | 845 | const char *options; |
e83bebef LP |
846 | int r; |
847 | ||
848 | assert(dest); | |
849 | assert(m); | |
850 | ||
a5648b80 | 851 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
68cf43c3 | 852 | if (r < 0) |
ec57bd42 | 853 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); |
8ce48cf0 LP |
854 | if (r == 0) { /* Doesn't exist yet? */ |
855 | r = mkdir_label(where, 0755); | |
856 | if (r < 0) | |
857 | return log_error_errno(r, "Creating mount point for overlay %s failed: %m", where); | |
858 | } | |
e83bebef LP |
859 | |
860 | (void) mkdir_p_label(m->source, 0755); | |
861 | ||
862 | lower = joined_and_escaped_lower_dirs(m->lower); | |
863 | if (!lower) | |
864 | return log_oom(); | |
865 | ||
86c0dd4a LP |
866 | escaped_source = shell_escape(m->source, ",:"); |
867 | if (!escaped_source) | |
868 | return log_oom(); | |
e83bebef | 869 | |
86c0dd4a | 870 | if (m->read_only) |
e83bebef | 871 | options = strjoina("lowerdir=", escaped_source, ":", lower); |
86c0dd4a LP |
872 | else { |
873 | _cleanup_free_ char *escaped_work_dir = NULL; | |
e83bebef | 874 | |
e83bebef LP |
875 | escaped_work_dir = shell_escape(m->work_dir, ",:"); |
876 | if (!escaped_work_dir) | |
877 | return log_oom(); | |
878 | ||
879 | options = strjoina("lowerdir=", lower, ",upperdir=", escaped_source, ",workdir=", escaped_work_dir); | |
880 | } | |
881 | ||
60e76d48 | 882 | return mount_verbose(LOG_ERR, "overlay", where, "overlay", m->read_only ? MS_RDONLY : 0, options); |
e83bebef LP |
883 | } |
884 | ||
de40a303 LP |
885 | static int mount_inaccessible(const char *dest, CustomMount *m) { |
886 | _cleanup_free_ char *where = NULL; | |
887 | const char *source; | |
888 | struct stat st; | |
889 | int r; | |
890 | ||
891 | assert(dest); | |
892 | assert(m); | |
893 | ||
a5648b80 | 894 | r = chase_symlinks_and_stat(m->destination, dest, CHASE_PREFIX_ROOT, &where, &st, NULL); |
de40a303 LP |
895 | if (r < 0) { |
896 | log_full_errno(m->graceful ? LOG_DEBUG : LOG_ERR, r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
897 | return m->graceful ? 0 : r; | |
898 | } | |
899 | ||
900 | assert_se(source = mode_to_inaccessible_node(st.st_mode)); | |
901 | ||
902 | r = mount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, source, where, NULL, MS_BIND, NULL); | |
903 | if (r < 0) | |
904 | return m->graceful ? 0 : r; | |
905 | ||
906 | r = mount_verbose(m->graceful ? LOG_DEBUG : LOG_ERR, NULL, where, NULL, MS_BIND|MS_RDONLY|MS_REMOUNT, NULL); | |
2c9b7a7e LP |
907 | if (r < 0) { |
908 | umount_verbose(where); | |
de40a303 | 909 | return m->graceful ? 0 : r; |
2c9b7a7e | 910 | } |
de40a303 LP |
911 | |
912 | return 0; | |
913 | } | |
914 | ||
915 | static int mount_arbitrary(const char *dest, CustomMount *m) { | |
916 | _cleanup_free_ char *where = NULL; | |
917 | int r; | |
918 | ||
919 | assert(dest); | |
920 | assert(m); | |
921 | ||
a5648b80 | 922 | r = chase_symlinks(m->destination, dest, CHASE_PREFIX_ROOT|CHASE_NONEXISTENT, &where, NULL); |
de40a303 LP |
923 | if (r < 0) |
924 | return log_error_errno(r, "Failed to resolve %s/%s: %m", dest, m->destination); | |
925 | if (r == 0) { /* Doesn't exist yet? */ | |
926 | r = mkdir_p_label(where, 0755); | |
927 | if (r < 0) | |
928 | return log_error_errno(r, "Creating mount point for mount %s failed: %m", where); | |
929 | } | |
930 | ||
931 | return mount_verbose(LOG_ERR, m->source, where, m->type_argument, 0, m->options); | |
932 | } | |
933 | ||
e83bebef LP |
934 | int mount_custom( |
935 | const char *dest, | |
88614c8a | 936 | CustomMount *mounts, size_t n, |
e091a5df | 937 | uid_t uid_shift, |
de40a303 | 938 | const char *selinux_apifs_context, |
5f0a6347 | 939 | MountSettingsMask mount_settings) { |
e83bebef | 940 | |
88614c8a | 941 | size_t i; |
e83bebef LP |
942 | int r; |
943 | ||
944 | assert(dest); | |
945 | ||
946 | for (i = 0; i < n; i++) { | |
947 | CustomMount *m = mounts + i; | |
948 | ||
bd6609eb | 949 | if (FLAGS_SET(mount_settings, MOUNT_IN_USERNS) != m->in_userns) |
5f0a6347 DDM |
950 | continue; |
951 | ||
bd6609eb | 952 | if (FLAGS_SET(mount_settings, MOUNT_ROOT_ONLY) && !path_equal(m->destination, "/")) |
5f0a6347 DDM |
953 | continue; |
954 | ||
bd6609eb | 955 | if (FLAGS_SET(mount_settings, MOUNT_NON_ROOT_ONLY) && path_equal(m->destination, "/")) |
de40a303 LP |
956 | continue; |
957 | ||
e83bebef LP |
958 | switch (m->type) { |
959 | ||
960 | case CUSTOM_MOUNT_BIND: | |
961 | r = mount_bind(dest, m); | |
962 | break; | |
963 | ||
964 | case CUSTOM_MOUNT_TMPFS: | |
e091a5df | 965 | r = mount_tmpfs(dest, m, uid_shift, selinux_apifs_context); |
e83bebef LP |
966 | break; |
967 | ||
968 | case CUSTOM_MOUNT_OVERLAY: | |
969 | r = mount_overlay(dest, m); | |
970 | break; | |
971 | ||
de40a303 LP |
972 | case CUSTOM_MOUNT_INACCESSIBLE: |
973 | r = mount_inaccessible(dest, m); | |
974 | break; | |
975 | ||
976 | case CUSTOM_MOUNT_ARBITRARY: | |
977 | r = mount_arbitrary(dest, m); | |
978 | break; | |
979 | ||
e83bebef LP |
980 | default: |
981 | assert_not_reached("Unknown custom mount type"); | |
982 | } | |
983 | ||
984 | if (r < 0) | |
985 | return r; | |
986 | } | |
987 | ||
988 | return 0; | |
989 | } | |
990 | ||
e091a5df | 991 | static int setup_volatile_state(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
992 | |
993 | _cleanup_free_ char *buf = NULL; | |
994 | const char *p, *options; | |
995 | int r; | |
996 | ||
997 | assert(directory); | |
998 | ||
e5b43a04 | 999 | /* --volatile=state means we simply overmount /var with a tmpfs, and the rest read-only. */ |
e83bebef | 1000 | |
64e82c19 | 1001 | r = bind_remount_recursive(directory, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
1002 | if (r < 0) |
1003 | return log_error_errno(r, "Failed to remount %s read-only: %m", directory); | |
1004 | ||
1005 | p = prefix_roota(directory, "/var"); | |
1006 | r = mkdir(p, 0755); | |
1007 | if (r < 0 && errno != EEXIST) | |
1008 | return log_error_errno(errno, "Failed to create %s: %m", directory); | |
1009 | ||
1010 | options = "mode=755"; | |
2fa017f1 | 1011 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef LP |
1012 | if (r < 0) |
1013 | return log_oom(); | |
1014 | if (r > 0) | |
1015 | options = buf; | |
1016 | ||
60e76d48 | 1017 | return mount_verbose(LOG_ERR, "tmpfs", p, "tmpfs", MS_STRICTATIME, options); |
e83bebef LP |
1018 | } |
1019 | ||
e091a5df | 1020 | static int setup_volatile_yes(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
e83bebef LP |
1021 | |
1022 | bool tmpfs_mounted = false, bind_mounted = false; | |
1023 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
07b9f3f0 | 1024 | _cleanup_free_ char *buf = NULL, *bindir = NULL; |
e83bebef | 1025 | const char *f, *t, *options; |
07b9f3f0 | 1026 | struct stat st; |
e83bebef LP |
1027 | int r; |
1028 | ||
1029 | assert(directory); | |
1030 | ||
07b9f3f0 LP |
1031 | /* --volatile=yes means we mount a tmpfs to the root dir, and the original /usr to use inside it, and |
1032 | * that read-only. Before we start setting this up let's validate if the image has the /usr merge | |
1033 | * implemented, and let's output a friendly log message if it hasn't. */ | |
1034 | ||
1035 | bindir = path_join(directory, "/bin"); | |
1036 | if (!bindir) | |
1037 | return log_oom(); | |
1038 | if (lstat(bindir, &st) < 0) { | |
1039 | if (errno != ENOENT) | |
1040 | return log_error_errno(errno, "Failed to stat /bin directory below image: %m"); | |
1041 | ||
1042 | /* ENOENT is fine, just means the image is probably just a naked /usr and we can create the | |
1043 | * rest. */ | |
1044 | } else if (S_ISDIR(st.st_mode)) | |
1045 | return log_error_errno(SYNTHETIC_ERRNO(EISDIR), | |
1046 | "Sorry, --volatile=yes mode is not supported with OS images that have not merged /bin/, /sbin/, /lib/, /lib64/ into /usr/. " | |
1047 | "Please work with your distribution and help them adopt the merged /usr scheme."); | |
1048 | else if (!S_ISLNK(st.st_mode)) | |
1049 | return log_error_errno(SYNTHETIC_ERRNO(EINVAL), | |
1050 | "Error starting image: if --volatile=yes is used /bin must be a symlink (for merged /usr support) or non-existent (in which case a symlink is created automatically)."); | |
e83bebef LP |
1051 | |
1052 | if (!mkdtemp(template)) | |
1053 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1054 | ||
1055 | options = "mode=755"; | |
2fa017f1 | 1056 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); |
e83bebef | 1057 | if (r < 0) |
c55d0ae7 | 1058 | goto fail; |
e83bebef LP |
1059 | if (r > 0) |
1060 | options = buf; | |
1061 | ||
60e76d48 ZJS |
1062 | r = mount_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); |
1063 | if (r < 0) | |
e83bebef | 1064 | goto fail; |
e83bebef LP |
1065 | |
1066 | tmpfs_mounted = true; | |
1067 | ||
1068 | f = prefix_roota(directory, "/usr"); | |
1069 | t = prefix_roota(template, "/usr"); | |
1070 | ||
1071 | r = mkdir(t, 0755); | |
1072 | if (r < 0 && errno != EEXIST) { | |
1073 | r = log_error_errno(errno, "Failed to create %s: %m", t); | |
1074 | goto fail; | |
1075 | } | |
1076 | ||
60e76d48 ZJS |
1077 | r = mount_verbose(LOG_ERR, f, t, NULL, MS_BIND|MS_REC, NULL); |
1078 | if (r < 0) | |
e83bebef | 1079 | goto fail; |
e83bebef LP |
1080 | |
1081 | bind_mounted = true; | |
1082 | ||
64e82c19 | 1083 | r = bind_remount_recursive(t, MS_RDONLY, MS_RDONLY, NULL); |
e83bebef LP |
1084 | if (r < 0) { |
1085 | log_error_errno(r, "Failed to remount %s read-only: %m", t); | |
1086 | goto fail; | |
1087 | } | |
1088 | ||
60e76d48 ZJS |
1089 | r = mount_verbose(LOG_ERR, template, directory, NULL, MS_MOVE, NULL); |
1090 | if (r < 0) | |
e83bebef | 1091 | goto fail; |
e83bebef LP |
1092 | |
1093 | (void) rmdir(template); | |
1094 | ||
1095 | return 0; | |
1096 | ||
1097 | fail: | |
1098 | if (bind_mounted) | |
60e76d48 | 1099 | (void) umount_verbose(t); |
e83bebef LP |
1100 | |
1101 | if (tmpfs_mounted) | |
60e76d48 | 1102 | (void) umount_verbose(template); |
e83bebef LP |
1103 | (void) rmdir(template); |
1104 | return r; | |
1105 | } | |
b53ede69 | 1106 | |
e091a5df | 1107 | static int setup_volatile_overlay(const char *directory, uid_t uid_shift, const char *selinux_apifs_context) { |
6c610aca LP |
1108 | |
1109 | _cleanup_free_ char *buf = NULL, *escaped_directory = NULL, *escaped_upper = NULL, *escaped_work = NULL; | |
1110 | char template[] = "/tmp/nspawn-volatile-XXXXXX"; | |
1111 | const char *upper, *work, *options; | |
1112 | bool tmpfs_mounted = false; | |
1113 | int r; | |
1114 | ||
1115 | assert(directory); | |
1116 | ||
1117 | /* --volatile=overlay means we mount an overlayfs to the root dir. */ | |
1118 | ||
1119 | if (!mkdtemp(template)) | |
1120 | return log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1121 | ||
1122 | options = "mode=755"; | |
1123 | r = tmpfs_patch_options(options, uid_shift == 0 ? UID_INVALID : uid_shift, selinux_apifs_context, &buf); | |
1124 | if (r < 0) | |
1125 | goto finish; | |
1126 | if (r > 0) | |
1127 | options = buf; | |
1128 | ||
1129 | r = mount_verbose(LOG_ERR, "tmpfs", template, "tmpfs", MS_STRICTATIME, options); | |
1130 | if (r < 0) | |
1131 | goto finish; | |
1132 | ||
1133 | tmpfs_mounted = true; | |
1134 | ||
1135 | upper = strjoina(template, "/upper"); | |
1136 | work = strjoina(template, "/work"); | |
1137 | ||
1138 | if (mkdir(upper, 0755) < 0) { | |
1139 | r = log_error_errno(errno, "Failed to create %s: %m", upper); | |
1140 | goto finish; | |
1141 | } | |
1142 | if (mkdir(work, 0755) < 0) { | |
1143 | r = log_error_errno(errno, "Failed to create %s: %m", work); | |
1144 | goto finish; | |
1145 | } | |
1146 | ||
1147 | /* And now, let's overmount the root dir with an overlayfs that uses the root dir as lower dir. It's kinda nice | |
1148 | * that the kernel allows us to do that without going through some mount point rearrangements. */ | |
1149 | ||
1150 | escaped_directory = shell_escape(directory, ",:"); | |
1151 | escaped_upper = shell_escape(upper, ",:"); | |
1152 | escaped_work = shell_escape(work, ",:"); | |
1153 | if (!escaped_directory || !escaped_upper || !escaped_work) { | |
1154 | r = -ENOMEM; | |
1155 | goto finish; | |
1156 | } | |
1157 | ||
1158 | options = strjoina("lowerdir=", escaped_directory, ",upperdir=", escaped_upper, ",workdir=", escaped_work); | |
1159 | r = mount_verbose(LOG_ERR, "overlay", directory, "overlay", 0, options); | |
1160 | ||
1161 | finish: | |
1162 | if (tmpfs_mounted) | |
1163 | (void) umount_verbose(template); | |
1164 | ||
1165 | (void) rmdir(template); | |
1166 | return r; | |
1167 | } | |
1168 | ||
e5b43a04 LP |
1169 | int setup_volatile_mode( |
1170 | const char *directory, | |
1171 | VolatileMode mode, | |
e091a5df | 1172 | uid_t uid_shift, |
e5b43a04 LP |
1173 | const char *selinux_apifs_context) { |
1174 | ||
1175 | switch (mode) { | |
1176 | ||
1177 | case VOLATILE_YES: | |
e091a5df | 1178 | return setup_volatile_yes(directory, uid_shift, selinux_apifs_context); |
e5b43a04 LP |
1179 | |
1180 | case VOLATILE_STATE: | |
e091a5df | 1181 | return setup_volatile_state(directory, uid_shift, selinux_apifs_context); |
e5b43a04 | 1182 | |
6c610aca | 1183 | case VOLATILE_OVERLAY: |
e091a5df | 1184 | return setup_volatile_overlay(directory, uid_shift, selinux_apifs_context); |
6c610aca | 1185 | |
e5b43a04 LP |
1186 | default: |
1187 | return 0; | |
1188 | } | |
1189 | } | |
1190 | ||
b53ede69 PW |
1191 | /* Expects *pivot_root_new and *pivot_root_old to be initialised to allocated memory or NULL. */ |
1192 | int pivot_root_parse(char **pivot_root_new, char **pivot_root_old, const char *s) { | |
1193 | _cleanup_free_ char *root_new = NULL, *root_old = NULL; | |
1194 | const char *p = s; | |
1195 | int r; | |
1196 | ||
1197 | assert(pivot_root_new); | |
1198 | assert(pivot_root_old); | |
1199 | ||
1200 | r = extract_first_word(&p, &root_new, ":", EXTRACT_DONT_COALESCE_SEPARATORS); | |
1201 | if (r < 0) | |
1202 | return r; | |
1203 | if (r == 0) | |
1204 | return -EINVAL; | |
1205 | ||
1206 | if (isempty(p)) | |
1207 | root_old = NULL; | |
1208 | else { | |
1209 | root_old = strdup(p); | |
1210 | if (!root_old) | |
1211 | return -ENOMEM; | |
1212 | } | |
1213 | ||
1214 | if (!path_is_absolute(root_new)) | |
1215 | return -EINVAL; | |
1216 | if (root_old && !path_is_absolute(root_old)) | |
1217 | return -EINVAL; | |
1218 | ||
1219 | free_and_replace(*pivot_root_new, root_new); | |
1220 | free_and_replace(*pivot_root_old, root_old); | |
1221 | ||
1222 | return 0; | |
1223 | } | |
1224 | ||
1225 | int setup_pivot_root(const char *directory, const char *pivot_root_new, const char *pivot_root_old) { | |
1226 | _cleanup_free_ char *directory_pivot_root_new = NULL; | |
1227 | _cleanup_free_ char *pivot_tmp_pivot_root_old = NULL; | |
1228 | char pivot_tmp[] = "/tmp/nspawn-pivot-XXXXXX"; | |
1229 | bool remove_pivot_tmp = false; | |
1230 | int r; | |
1231 | ||
1232 | assert(directory); | |
1233 | ||
1234 | if (!pivot_root_new) | |
1235 | return 0; | |
1236 | ||
1237 | /* Pivot pivot_root_new to / and the existing / to pivot_root_old. | |
1238 | * If pivot_root_old is NULL, the existing / disappears. | |
1239 | * This requires a temporary directory, pivot_tmp, which is | |
1240 | * not a child of either. | |
1241 | * | |
1242 | * This is typically used for OSTree-style containers, where | |
1243 | * the root partition contains several sysroots which could be | |
1244 | * run. Normally, one would be chosen by the bootloader and | |
1245 | * pivoted to / by initramfs. | |
1246 | * | |
1247 | * For example, for an OSTree deployment, pivot_root_new | |
1248 | * would be: /ostree/deploy/$os/deploy/$checksum. Note that this | |
1249 | * code doesn’t do the /var mount which OSTree expects: use | |
1250 | * --bind +/sysroot/ostree/deploy/$os/var:/var for that. | |
1251 | * | |
1252 | * So in the OSTree case, we’ll end up with something like: | |
1253 | * - directory = /tmp/nspawn-root-123456 | |
1254 | * - pivot_root_new = /ostree/deploy/os/deploy/123abc | |
1255 | * - pivot_root_old = /sysroot | |
1256 | * - directory_pivot_root_new = | |
1257 | * /tmp/nspawn-root-123456/ostree/deploy/os/deploy/123abc | |
1258 | * - pivot_tmp = /tmp/nspawn-pivot-123456 | |
1259 | * - pivot_tmp_pivot_root_old = /tmp/nspawn-pivot-123456/sysroot | |
1260 | * | |
1261 | * Requires all file systems at directory and below to be mounted | |
1262 | * MS_PRIVATE or MS_SLAVE so they can be moved. | |
1263 | */ | |
c6134d3e LP |
1264 | directory_pivot_root_new = path_join(directory, pivot_root_new); |
1265 | if (!directory_pivot_root_new) | |
1266 | return log_oom(); | |
b53ede69 PW |
1267 | |
1268 | /* Remount directory_pivot_root_new to make it movable. */ | |
1269 | r = mount_verbose(LOG_ERR, directory_pivot_root_new, directory_pivot_root_new, NULL, MS_BIND, NULL); | |
1270 | if (r < 0) | |
1271 | goto done; | |
1272 | ||
1273 | if (pivot_root_old) { | |
1274 | if (!mkdtemp(pivot_tmp)) { | |
1275 | r = log_error_errno(errno, "Failed to create temporary directory: %m"); | |
1276 | goto done; | |
1277 | } | |
1278 | ||
1279 | remove_pivot_tmp = true; | |
c6134d3e LP |
1280 | pivot_tmp_pivot_root_old = path_join(pivot_tmp, pivot_root_old); |
1281 | if (!pivot_tmp_pivot_root_old) { | |
1282 | r = log_oom(); | |
1283 | goto done; | |
1284 | } | |
b53ede69 PW |
1285 | |
1286 | r = mount_verbose(LOG_ERR, directory_pivot_root_new, pivot_tmp, NULL, MS_MOVE, NULL); | |
1287 | if (r < 0) | |
1288 | goto done; | |
1289 | ||
1290 | r = mount_verbose(LOG_ERR, directory, pivot_tmp_pivot_root_old, NULL, MS_MOVE, NULL); | |
1291 | if (r < 0) | |
1292 | goto done; | |
1293 | ||
1294 | r = mount_verbose(LOG_ERR, pivot_tmp, directory, NULL, MS_MOVE, NULL); | |
1295 | if (r < 0) | |
1296 | goto done; | |
1297 | } else { | |
1298 | r = mount_verbose(LOG_ERR, directory_pivot_root_new, directory, NULL, MS_MOVE, NULL); | |
1299 | if (r < 0) | |
1300 | goto done; | |
1301 | } | |
1302 | ||
1303 | done: | |
1304 | if (remove_pivot_tmp) | |
1305 | (void) rmdir(pivot_tmp); | |
1306 | ||
1307 | return r; | |
1308 | } |